This invention relates to a method and apparatus for the stretching of flexible devices that are used to join objects together. Such devices, which are commonly known as "fasteners" have gained wide industrial and commercial acceptance. As shown, for example, in U.S. Pat. No. 3,875,648, the fasteners can be formed by a thin flexible filament, typically of plastic with an enlarged head at each end. Such fasteners are used to attach buttons to garments, tags to merchandise, in matching pairs of shoes and socks, and generally for the temporary or permanent joinder of items.
The fasteners typically are provided in an assemblage, and individual fasteners are secured, as needed, from the assemblage. There are two basic types of fastener assemblage. In the first type, as disclosed in U.S. Pat. Nos. 3,103,666; 3,380,122; and 3,399,432, the individual fasteners have filaments that extend to cross bars which are in turn joined to a support rod by severable necks. The filaments of the fasteners are stretched to decrease their diameters and to strengthen their joinder to the cross bars. The filaments can be stretched within the mold by which the fasteners are formed, as illustrated in U.S. Pat. No. 3,380,122, or they can be stretched independently of the mold as illustrated by U.S. Pat. No. 3,457,589. The resulting fasteners can be applied by the dispensers illustrated in U.S. Pat. Nos. 3,103,666; 3,470,834; 3,759,435; and 3,875,648.
In the second type of assemblage, as shown in U.S. Pat. No. 3,875,648, two opposed longitudinally extending side members are joined together by regularly spaced and transversely extending filaments. Individual fasteners are severed from the side members between adjoining filaments. The latter are desirably stretched either in the mold in which they are formed, or outside the mold.
The foregoing procedures and apparatus for the stretching of fasteners are relatively slow and expensive.
Accordingly, it is an object of the invention to expedite the formation of fasteners for the attachment of items. A related object is to expedite the formation of assemblages of attachments.
A further object of the invention is to facilitate the stretching of fasteners. A related object is to facilitate the stretching of assemblages of attachments.
Other objects of the invention will become apparent from the description of the invention set forth below.